1. Field of the Invention
The present invention is directed to a system for collecting and encapsulating bulk waste or salvageable products. More specifically, the present invention is directed to a system to collect a variety of bulk materials, including hazardous waste materials, utilizing principals of pneumatic conveyance.
2. Background
A variety of industries generate significant quantities of waste by-products as a normal part of their day-to-day operation. In most instances, these materials must be periodically removed and transported to a waste disposal, reclamation or treatment site or other similar facility. Such materials may include silica powders, fly ash, sludges, asbestos-containing materials, spent catalyst components, and more mundane materials such as bricks, grease or woodchips.
Collection, transportation and disposal of waste products is both expensive and labor intensive. Traditionally, removal and transportation of dry waste products was carried out via the use of heavy, conventional machinery such as front-end loaders and open carriers. The use of such machinery, however, had a number of disadvantages. If a finely particulated material such as silica powder was involved, the use of open equipment often resulted in an undesirable creation of dust. This creation of dust often posed a danger to equipment, operating personnel and the environment. The use of such machinery also did not lend itself to use with sludges or other liquid or semi-solid wastes. Importantly, conventional removal and transportation techniques generally necessitated rigorous decontamination of both the equipment and personnel involved in the clean-up operation. The efforts directed toward such decontamination were especially pronounced when the waste products included asbestos or other known contaminants.
Other prior art collection and removal systems include vacuum-type removal apparatus. Vacuum-type mechanisms have long been used to collect a variety of liquid and semi-solid type waste. Conventional vacuum-type collection systems, however, generally cannot be used where the vacuum operation involves a significant head height, e.g., a head height in excess of approximately 30 feet. Moreover, such vacuum systems have little if any application to the collection of particulate-type waste products such as sands or powders.
In approximately 1979, assignee Allwaste Services of Texas, Inc. developed a system which enabled the collection of bulk material in a roll-off container modified to operate in association with a conventional air mover. Air moving is generally defined as a vacuuming process by which waste or salvageable materials are removed by means of pneumatic conveyance (i.e., vacuuming with controlled air velocity). An air moving truck (i.e., air mover) uses either a positive displacement blower or centrifugal fan to provide the movement or velocity of air. In these early designs, air was exhausted from the container by means of the air mover, which resulted in the creation of suction through an air intake. When a hose or pipe was coupled to this air intake, both liquid and solid materials could be conveyed through the hose or pipe and collected in the container.
In these early designs, the collection container was adapted to receive a liner which was suspended from its interior via a series of mounting hooks. When the container was filled, it was transported to the dump site via a roll-off truck or trailer whereby the liner and its contents were "dumped" from the container. This was normally carried out by inclining the container on the roll-off truck in a conventional fashion. Due to the nature of the liner and its mounting in the container, however, removal of the liner and its contents often resulted in contamination of the container interior. As a result of such contamination, the interior of the container necessitated costly cleaning after each use. Predictably, such contamination was undesirable in instances involving hazardous compounds such as asbestos or the like. Additionally, such contamination posed the possibility of damage to the container when the waste materials or salvageable compounds involved corrosive compounds.